Grade Eight Science Notes – Unit One (Cells)

Table of Contents:

Unit 1 Notes-Cells  1

Guiding Question: 1

Area of Interaction: 2

IB Learner Profile: 2

Science Notes-DNA, Microscope Parts  2

What Defines A Living Thing?  2

Cell Theory: 2

Care and Use of Microscopes: 3

Cell Parts: 3

Cellular Organisms: 4

Membrane: The Flow of Materials Into and Out of Cells (Permeability): 4

Diffusion: 4

Osmosis: 4

Questions pg 30, 32-33: 5

Unit Test Solution: 5

Sept 11/09

Unit 1 Notes-Cells

Guiding Question: How can you prepare for your hereditary disposition?

Hereditary disposition is a medical condition that is carried from generation to generation and usually cannot be avoided. Hereditary means something biological passed on from the parents, genes-generation. Disposition means a person’s habits, aspects or temperaments. How can we prepare for the habits and characters?

Area of Interaction:

Ø  Health and Social Education

Ø  Approaches to Learning

IB Learner Profile:

Ø  Reflective

Ø  Thinkers

Ø  Knowledgeable

Ø  Inquirer

Sept 15/09

Science Notes-DNA, Microscope Parts

DNA Testing

Ø  DNA made of 3 billion base pairs, when a mistake happens in a pair, that is where a medical condition happens

Ø  Able to find medical conditions when testing DNA and ancestry

Ø  Testing for DNA can help people get the treatment they need

Ø  Not always correct

Ø  Ancestry tracking back to 35,000 years

Ø  Hard to track ancestry of different ethnicity

Ø  Best results with European descent

Ø  Some DNA test companies hide some results because they don’t think you want to know

Ø  Critics say that the DNA tests are inaccurate because of the sharing of genes

Ø  Not regulated so could be completely wrong

Microscope-pg14

Ø  Compound light microscope uses light through different lenses to form an image of the specimen

Ø  Eyepiece-magnifies object usually to 10x, look through it

Ø  Coarse adjustment knob-move stage holding object closer or farther for different views

Ø  Fine adjustment knob-sharpen image

Ø  Revolving nosepiece-objective lenses attached to rotate them

Ø  Objective lenses-low power 4x, medium power 10x and high power 40x

Ø  Stage-where the object is placed

Ø  Stage clips-to keep the slide in place

Ø  Diaphragm-different holes to let different amounts of light in

Ø  Lamp-emits light to look at the slide or a mirror is used to collect light

Ø  Arm-holds the tube and used to carry microscope